Abstract: A Battery Management System (BMS) inspects a battery pack using AC impedance. A controller on the BMS drives a Pulse-Width Modulation (PWM) output signal to an on-board excitation regulator such as a synchronous buck converter that modulates a limited energy unit such as a capacitor with a swept frequency of a PWM input signal. The capacitor modulations are applied to a terminal of the battery pack as an AC excitation signal. Synchronous sampling of the battery pack provides responses to the AC excitation signal. An AC excitation signal current and a battery response voltage are processed and Fourier-transformed to generate a Nyquist plot of the excitation-response data. Curve shifts can indicate worn battery cells. The capacitor generating the AC excitation signal draws little energy from the battery pack so AC impedance inspection can occur during all modes: charging, discharging, and idle modes without an external power supply.

Abstract: In a wireless power transfer (WPT) system, a power-transmitting unit has a loop-shaped magnetic core formed by alternately arranging high-permeability (HP) and low-permeability (LP) core sections to give an interleaving pattern. A primary coil wound on the magnetic core provides a magnetic flux traveling therein when excited by an AC power source. A power-receiving unit has a pickup core shaped and dimensioned to overlie one or any LP core section, and to partially overlap HP core sections immediately adjacent to the LP core section that is overlay. The pickup core has a relative permeability higher than that of the aforesaid LP core section, causing at least a part of the magnetic flux to divert from this LP core section to the pickup core. The diverted part of magnetic flux generates electrical power in a secondary pickup coil wound on the pickup core to achieve WPT.

Abstract: In a wireless power transfer (WPT) system, a power-transmitting unit has a loop-shaped magnetic core formed by alternately arranging high-permeability (HP) and low-permeability (LP) core sections to give an interleaving pattern. A primary coil wound on the magnetic core provides a magnetic flux traveling therein when excited by an AC power source. A power-receiving unit has a pickup core shaped and dimensioned to overlie one or any LP core section, and to partially overlap HP core sections immediately adjacent to the LP core section that is overlay. The pickup core has a relative permeability higher than that of the aforesaid LP core section, causing at least a part of the magnetic flux to divert from this LP core section to the pickup core. The diverted part of magnetic flux generates electrical power in a secondary pickup coil wound on the pickup core to achieve WPT.